Some issues about the function main_ctx_init

1. The length of the macro MAX_PATH is only 260, isn't it really too small?
2. The logdir directly reads the running directory, then creates and uses the directory logs in this directory. Even if the directory was modified later, an empty directory has already been created here.
3. The configuration file directory should have a rollback: first try the current directory (not the current directory/etc), then try the directory /usr/local/etc if it does not exist, and finally try the directory /etc.

The main issue is that the directory will be automatically created before customizing the path.